Let It Rain

The last time I wrote about rain gardens I was a skeptic. I saw them as just a passing fad and another way to sell landscape design and new plants. It was also a time when climate change had more than a few doubters. Like I said, I was a skeptic.

But after a number of classes and lectures on climate change and seeing historical data from the National Weather Service, I’m no longer a skeptic. And one of the tidbits that I’ve walked away with is that we are in for more and more short but heavy rain events, as opposed to the slow and steady rains we may remember from years ago that lasted for days.So if these short-duration but high-volume rain events are what’s in store for our future, where will all this quickly accumulating water go? If we allow it to simply run off our driveways, parking lots and highways, along with it goes a number of different kinds of pollution and sediment.

In large residential and commercial developments, fairly large stormwater containment systems are now required by law to control this water and treat" it as well, but naturally. State and local governments are being required to upgrade drainage culverts and devices to reduce the velocity of water flow along highways and major interstates.

For us, there are rain gardens. And they’re not your backyard puddles anymore. They have the ability to capture large amounts of water, release it slowly back into our aquifers and clean it in the process. It works on even the smallest properties, and you may be surprised, if you’re about to put up a new home, to see a rain garden show up in your landscape plans.

Have a place on your property that always seems to flood after a rain? Have a spot where water drains from other areas on your property to a depression and stays there for hours? Thinking about doing some work in a regulated wetland that will require permits and mitigation? Building a new house or putting on an addition that will require planning and zoning approvals? Chances are a rain garden may or should be in your future.

So what exactly is a rain garden? It’s a shallow, vegetated depression designed to absorb and filter runoff from hard surfaces (impervious surfaces) like roofs, roads, sidewalks, driveways, parking areas and solid-surface tennis courts. In order for a rain garden to be sustainable, it’s usually planted with native herbaceous plants and grasses that can tolerate periods of inundation as well as periods of drought. When properly constructed, this garden should be attractive and be able to conserve water and protect the quality of the water that goes back into our underground aquifer or out into the bays.

The next logical question is, how does this rain garden really help? Well, as we become more and more urbanized, our original native landscapes and quick-draining sandy soils are being replaced by impervious surfaces that prevent rainwater from soaking into the ground. Stormwater quickly runs off these hard surfaces, picking up pollutants, and carries them into streams, creeks, our bays, ponds, lakes and tidal wetlands, to say nothing of the ocean. This rapidly flowing water also increases the chances for flash flooding and erosion, as you’ll often see after a downpour.

The goal of a rain garden is to keep water on the land and to allow it to filter into the soil. This provides not only water for the plants but also a more constant flow of water down into our groundwater. And when the right plants are used, they help filter out a wide range of pollutants including fertilizers, pesticides, oil, heavy metals and other chemicals that otherwise get into our groundwater and bays. And keep in mind that by reducing the amount of water that runs off your property, because it's going into your rain garden, you are lowering the risk of community flooding and erosion.

There’s lots of help available if you want to create your own rain garden, and they also make great community projects for garden clubs and environmental groups.

I’ve really simplified the process, but the six steps I've listed are the basics. Use this Google link, http://goo.gl/00Clxq, to take you to a great handbook that goes into much more detail and has plenty of charts, pictures and directions that you’ll find incredibly helpful. There’s also a rain garden app from the University of Connecticut, and their handbook is here http://goo.gl/nULAtW. Keep growing.

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